The Students' Guide in Quantitative Analysis - Free Ebooks Library

I
DETERMINATION OF TOTAL CAKOON. 8i
I Method of Alvaroonzalez. See Am. Chem., Vol. V..
p_ 4jjr.—Place 10 grms. of borings in a beaker and treat
with a solution of cupric sulpliate (40 grms. CuSO^ in 200
200 ^,.c. l"IiO), stirring until the reaction ceases. Add di-
lute HNOj gradually, and let stand until the copper has dis-
solved.
Dilute the solution and filter through one of Rotli-
er's fialf filters (described in Chem. Neivs, Jan. 30, 1874,
p. 57), wash thoroughly, and dry on funnel at 100* C.
Detach ppt. from filter carefully, place in a weighed cru-
cible (thrONY away filter), dry at 100° C, and weigh. Ignite
and weigh again; the difference between two weighings
gives total carbon.
This method is not free from objections, but will answer
when great accuracy is not indispensable, and speedy results
are desirable.
2. Method employed by \."Lo\\nw.PC(i.^^\A^. 'S^^ Chemical
Phenomena ofIron Smelting, London, 1872.—Digest 3 grins,
borings from 24 to 48 hours with a solution of CuSO^ in
e-xcess, collect the spongy Cu+C+graphite on an asbestos
filter, and burn the carbon in a stream of oxygen gas, as in
the ultimate analysis of organic bodies collecting the CO,
in KHO solution. Cf. Analysis No. 30.
3. Method of Regnault and Bromeis. See Crookes'
Select Methods, p. 74,—Heat borings in a combustion tube
with a mixture of plumbic chromate and KClOj, collecting
the CO, in KHO.
4. Methods for the liberation of Combined Carbon are also
numerous.
:
{a) BoussiNGAULT triturates the iron in a porcelain mor-
tar with 15 to 20 parts of HgCl^ and sufficient water to
make a thin paste
Fe+2ligCl,=FeCU4-Hg,Cl,.